1. Field of the Invention
The invention relates to a cryptographic method. More particularly, the invention relates to a diffusion function working on a multidimensional diffusion-area (plaintext/ciphertext), and further, repeating the diffusion function for at least one time to create a multilayer effect in order to perform the encryption and the decryption.
2. Description of the Related Art
The Applicant's following patent applications are related to the invention and are incorporated herein by reference: “Diffused Data Encryption/Decryption Processing Method”, application Ser. No. 12/365,160, filed Feb. 3, 2009 (CIP of application Ser. No. 10/963,014, filed Oct. 12, 2004); “Multipoint Synchronous Diffused Encryption/Decryption Method”, application Ser. No. 11/171,549, filed Jun. 30, 2005.
The prior art described that the coding of a 2D diffusion-area, see application Ser. No. 12/365,160, page 7, teaches the math of A(i, j)=A⊕Aci⊕Arj⊕b(i, j); further expressed the status of diffusion from inward to outward or vice versa in reverse, and implemented to multidimensional matrix A(i1, i2, . . . in), see application Ser. No. 11/171,549, page 4, 7.
The present invention emphasizes the multilayer effect of multidimensional diffusion. The diffusion function herein is notated specially by AF(p1, p2, . . . pn) to differentiate from the traditional symbolization of matrix position.